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PatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.

Hormone production

The tumours that are often hormonally active are the eosinophilic GH-secreting adenomas, basophilic ACTH-secreting adenomas and prolactin-secreting adenomas. These tumours may protrude outside of the pituitary fossa (sella turcica):

ACTH-producing tumours: basophilic adenoma, presents with Cushing's disease. Enlargement of the tumour is usually slowly progressive. Initially confined to the sella turcica, but may enlarge and become invasive after bilateral adrenalectomy (Nelson's syndrome).

Prolactin-producing adenomas: usually intrasellar; are often small (less than 10 mm) but may become large enough to enlarge the sella turcica.

GH-producing tumours: eosinophilic - results in gigantism in children and acromegaly in adults. Suprasellar extension is not uncommon. Enlargement of the tumour is usually slowly progressive.

Non-functioning tumours: they cause symptoms by extension beyond the sella, resulting in pressure on surrounding structures. In the absence of endocrine symptoms, visual loss is the usual initial manifestation.

Presentation

Depends on the hormone secreted by the tumour as well as the pattern of growth of the tumour within the sella turcica.

Local effects resulting from an expanding pituitary mass:

An expanding mass within the pituitary fossa may give rise to headache, neuro-ophthalmological defects or facial pain according to the size and direction of expansion:

Headaches: are classically retro-orbital or bitemporal. They tend to be worse on waking. Sudden catastrophic headaches may result from pituitary apoplexy. Very large pituitary tumours may cause obstruction of CSF, resulting in hydrocephalus and expansion of the lateral ventricles.

Visual field defects: these are common but often asymptomatic. Bitemporal hemianopia is the classic abnormality but any unilateral or bilateral visual field defect may occur.

Ocular nerve palsies cause a squint.

Extensive extension into the hypothalamus may result in disorders of appetite, thirst, temperature regulation and consciousness.

Investigations

Endocrine studies for hormone hyposecretion and hypersecretion. See also the separate article on Pituitary Function Tests.

Lateral skull X-ray: may incidentally show enlargement of the fossa but is not a definitive investigation.

Visual fields: common defects are upper-temporal quadrantanopia and bitemporal hemianopia.

MRI scan is the preferred imaging investigation and is superior to CT scanning.[3]

Differential diagnosis

Other neoplasms of the sellar region include craniopharyngiomas, Rathke's cleft cysts, and, less commonly, meningiomas, germinomas, and hamartomas.[4]

Craniopharyngiomas are benign, cystic tumours found above the sella turcica. They present with headaches, visual field defects and hypopituitarism (including growth failure, as often present in childhood and adolescence).

Other causes of headache, visual field defects, visual disturbance and endocrine dysfunction.

Management

Treatment depends on the type of pituitary tumour and whether it extends into the brain around the pituitary. Hormone-secreting tumours can be treated by surgery, radiation therapy or by drugs such as bromocriptine (prolactin-secreting adenomas) or somatostatin analogues (GH-secreting adenomas). Small non-functioning adenomas and prolactinomas in asymptomatic patients do not require immediate intervention and can be observed.[5]

Surgery

Trans-sphenoidal surgery is the usual treatment of choice for lesions confined within the sella turcica and ACTH-secreting adenomas. Frontal craniotomy is rarely required. Lesions extending beyond the confines of the pituitary are most frequently non-functioning chromophobe adenomas and require additional radiation therapy. Rapid deterioration of vision is an immediate indication for surgery.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.

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